Sustainable use of agricultural residues to improve corn silage quality: Co-ensiling with oregano oil residues

Abstract

The study aimed to evaluate the effect of oregano essential oil extraction residues (ORES) on the fermentation quality of corn silage. Non-fungal infected (NFI) and fungal infected (FI) corn were ensiled with 20% (wet weight) of ORES for 180 d. The inclusion of ORES delayed pH decline regardless of fungal infection. The inclusion of ORES did not adversely affect lactic acid (LA) production in NFI silages but retarded the initial LA fermentation of FI silages. Co-ensiling corn with ORES significantly decreased ethanol content. Co-ensiling FI corn with ORES significantly increased the fungal Chao1 and Shannon indices compared to FI-CON silages but did not affect the bacterial Chao1 and Shannon indices. The fungal infection aggravated the risk of Paenibacillus and Clostridium contamination, which was mitigated by co-ensiling with ORES. In conclusion, fungal infection suppressed ensiling fermentation, and heightened the risk of proliferation of undesirable bacteria, while ORES relieved these risks. Ensiling ORES with corn as forages is a potential and promising strategy for the efficient reusing of agro-industrial waste.

Keywords: Anaerobic fermentation; Corn; Fungal infection; Oregano oil extraction residues.